The present invention relates generally to an exposure apparatus for exposing a pattern onto a semiconductor wafer. More particularly, the present invention relates to a stage assembly and an associated method for applying a compensating force to cancel a reaction force of a stage and an exposure apparatus, including the stage assembly, for manufacturing semiconductor wafers.
A stage assembly for an exposure apparatus typically includes a stage, which supports and moves a semiconductor wafer while the exposure apparatus transfers a circuit pattern onto the wafer. As the stage moves, however, it exerts a reaction force on other components of the stage assembly. This reaction force makes precise movement and positioning of the stage difficult because it tends to move and cause vibration on other components of the stage assembly. Accordingly, there is a need for a stage assembly that compensates for the reaction force exerted by a stage and thereby improves the exposure accuracy of an exposure apparatus.